[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2010/images/05/31/art.obama.gi.jpg caption="President Obama is spending Memorial Day in Chicago."](CNN) - From a wreath-laying ceremony at Virginia's Arlington National Cemetery to a moment of silence at Major League Baseball games across the country, America on Monday stops and remembers the sacrifices of those who fell in military service to the country.
Vice President Joe Biden will take the place of President Barack Obama for the traditional wreath-laying ceremony at Arlington, the most prestigious military cemetery in the country, where many of the soldiers killed in Iraq and Afghanistan are buried.
Many veteran and conservative bloggers have taken issue with Obama's absence.
"On Monday, it's where the eyes of our entire nation will be focused," said Paul Rieckhoff, founder of the Iraq and Afghanistan Veterans of America. "And unfortunately, the president and his family won't be there to stand with us."
Obama is in Chicago, Illinois, spending the night with his family at their home for the first time in more than a year. He will mark the holiday with remarks at the Abraham Lincoln National Cemetery, about an hour outside of Chicago.
Obama's absence from Memorial Day services at Arlington will not be unprecedented, but in recent years, it has been a common practice to attend.
President Bill Clinton went every year of his presidency, and President George W. Bush went each year except for the year he was in Europe to commemorate the D-Day anniversary. Presidents Ronald Reagan and George H.W. Bush did not attend regularly.
In New York, a restored B-17G Flying Fortress bomber will leave the American Airpower Museum airfield in Farmington at 12:30 p.m. and drop flowers into the waters of the Atlantic not far from the Twin Towers World Trade Center
The act will honor seven CIA personnel killed during a suicide attack at a military base in Khost, Afghanistan, in December.
"It is rare that we can publicly acknowledge the CIA's loss of brave men and women in the line of duty," said Jeff Clyman, museum president. "The knowledge that seven CIA personnel were killed at the hands of a terrorist compels us to pause and remember these patriots who fully understood the mortal danger they faced, and yet deliberately went into harm's way to protect our homeland and our lives."
Back in Washington, D.C., the Vietnam Veterans Memorial will officially recognize six names added to the black granite wall in May.
The addition brings the number of men and women who were killed or remain missing in action to 58,267.
Elsewhere, Major League Baseball games will stop at 3 p.m. ET to observe the National Moment of Remembrance.
"Helping our troops is a cause very close to my heart, and I'm glad to see Major League Baseball will once again pledge their support on Memorial Day and beyond," San Francisco Giants pitcher Barry Zito said in a statement.
Teams will don special "Stars & Stripes" caps, with the American flag etched into the teams' logos.
The moment - established by Congress - asks Americans to stop whatever they are doing and observe a minute's silence. The time 3 p.m. was chosen because it is when most Americans are enjoying their freedoms on the national holiday, the White House Commission on Remembrance said.
The idea for the moment was born when the commission director asked children touring Washington, D.C. what Memorial Day meant.
Some of the children responded that it was the day the pools open.